Okmulgee County is a county in the U.S. state of Oklahoma. As of the 2020 census, the population was 36,706. The county seat is Okmulgee. Located within the Muscogee Nation Reservation, the county was created at statehood in 1907. The name Okmulgee is derived from the Hitchita word okimulgi, meaning "boiling waters".

Tulsa is the second-most-populous city in the state of Oklahoma, after Oklahoma City, and is the 47th-most-populous city in the United States. The population was 413,066 as of the 2020 census. It is the principal municipality of the Tulsa metropolitan area, a region with 1,034,123 residents. The city serves as the county seat of Tulsa County, the most densely populated county in Oklahoma, with urban development extending into Osage, Rogers and Wagoner counties.